Background
Acupoints  used  in  treatment  may  or may  not  be in the same area of the body as the targeted symptom. The TCM theory for the selection of such points and their effectiveness is that they work by stimulating  the meridian system to bring about relief  by  rebalancing  yin,  yang  and qi (also spelled "chi"). This  theory  is  based on  the paradigm of TCM, not that of science. Many  East  Asian  martial  arts  also  make  extensive  study  and use of acupressure for self-defense and health purposes (chin na, tui na). The points or combinations of  points are said to  be  used  to  manipulate  or  incapacitate  an  opponent.  Also,  martial  artists  regularly  massage  their  own acupressure points in routines to remove blockages from their own meridians, claiming to thereby  enhance their circulation and flexibility and keeping the points "soft" or less vulnerable to an attack. Attacking  the acupressure points  is  one  theme  in  the  wuxia  genre  of  movies  and  novels.  Acupressure  might   work  via  release  of endogenous  opioid  analgesics  such  as  enkephalin,  endorphin  and  dynorphins  leading to alleviation of pain. Acupressure is considered to be a safe form of therapy and side effects are rare.

Research
A preliminary  randomized  trial of Tapas Acupressure Technique (TAT) found a possible weak correlation with weight  loss  maintenance  using  TAT  versus  Qigong  or  self-directed  support,  suggesting   that   TAT  might outperform  the  other  methods  studied. The  results  were  not  statistically  significant,  but  a  separation   test indicated that further study is warranted. A full randomized trial of TAT versus standard weightloss management intervention is currently being conducted, funded by the NCCAM. An acupressure wristband that is claimed to relieve the symptoms of motion sickness and other forms of nausea is available. The band is designed to provide pressure   to  the  P6  acupuncture  point,  a  point   that   has   been   extensively  investigated.  The   Cochrane Collaboration, a  group  of  evidence-based  medicine (EBM) reviewers, reviewed the use of P6 for nausea and vomiting, and found it to  be  effective  for  reducing  post-operative  nausea,  but  not  vomiting. The  Cochrane review included various means of  stimulating  P6,  including  acupuncture, electro-acupuncture,  transcutaneous nerve stimulation, laser stimulation, acustimulation device and acupressure; it did  not comment  on  whether one or more forms of stimulation were more effective. EBM reviewer  Bandolier  said  that  P6  acupressure  in  two studies showed 52% of patients with control having a success, compared with 75% with  P6  acupressure. One author  of  an  article  published  in  the  Scientific   Review  of   Alternative  Medicine  disagreed.  A  Cochrane Collaboration review found that massage provided some long-term benefit for low back pain, and said: It seems that  acupressure  or  pressure  point  massage  techniques  provide more relief than classic (Swedish) massage, although more research is needed to confirm this.

Criticism of TCM theory
Clinical  use  of  acupressure  frequently  relies  on  the  conceptual  framework of Traditional Chinese Medicine (TCM), which some scholars have characterized as pseudoscientific. There is no physically verifiable anatomical or  histological  basis  for  the  existence  of  acupuncture  points  or  meridians. Proponents reply that TCM is a prescientific system that continues to have practical relevance. Acupuncturists tend to  perceive TCM  concepts in functional rather than structural terms (e.g., as being useful in guiding evaluation and care of patients).